The present invention relates to vehicle obstruction sensing and more particularly to a vehicle curb sensor.
Curb sensors for use facilitating vehicle parking conventionally employ a deflectable probe that is adjusted to rub against an obstruction when there is a predetermined clearance between the obstruction and the vehicle itself. An audible signal is produced from the probe as it rubs against the obstacle. Typically, a separate sensor is used on the curb side at each end of the vehicle. It is also known to generate an electrical signal that is responsive to contact between the probe and the obstruction for operating warning devices such as lamps, buzzers, and the like. Use of such electrical devices is appropriate for helping to distinguish between signals from the front and rear probes, especially when there are high levels of background noise, and when the user has impaired hearing.
The electrical parking sensors of the prior art exhibit a number of disadvantages, such as one or more of the following:
1. They are difficult to install in that they must be connected to a switched node of the vehicle electrical system to avoid excessive discharge of the vehicle battery when the vehicle is left unattended. A switched node, such as at the ignition switch is typically relatively inaccessible. Also, there must be additional wiring between exterior locations proximate the vehicle wheels to a location within the vehicle, wihch is awkward to provide.
2. The electrical warning devices are annoying in that the warning signal persists while the vehicle is at rest. Also, false warning indications are produced by random vibrations of the probes, such as is produced by the wind when driving at high speed.
Thus there is a need for a vehicle parking sensor that is effective for distinguishing front and rear obstructions in the presence of noise and for use by those having impaired hearing, which is inexpensive to produce and, most particularly, easy to install.